When the result of an EXTRACT_SUBREG, INSERT_SUBREG, or SUBREG_TO_REG

operator is used by a CopyToReg to export the value to a different
block, don't reuse the CopyToReg's register for the subreg operation
result if the register isn't precisely the right class for the
subreg operation.

Also, rename the h-registers.ll test, now that there are more
than one.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69087 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 39 insertions, 0 deletions

diff --git a/test/CodeGen/X86/h-registers-1.ll b/test/CodeGen/X86/h-registers-1.ll
new file mode 100644
index 0000000000..789f3dd18f
--- /dev/null
+++ b/test/CodeGen/X86/h-registers-1.ll
@@ -0,0 +1,39 @@
+; RUN: llvm-as < %s | llc -march=x86-64 > %t
+; RUN: grep {movzbl	%\[abcd\]h,} %t | count 8
+; RUN: grep {%\[abcd\]h} %t | not grep {%r\[\[:digit:\]\]*d}
+
+; LLVM creates virtual registers for values live across blocks
+; based on the type of the value. Make sure that the extracts
+; here use the GR64_NOREX register class for their result,
+; instead of plain GR64.
+
+define i64 @foo(i64 %a, i64 %b, i64 %c, i64 %d,
+                i64 %e, i64 %f, i64 %g, i64 %h) {
+  %sa = lshr i64 %a, 8
+  %A = and i64 %sa, 255
+  %sb = lshr i64 %b, 8
+  %B = and i64 %sb, 255
+  %sc = lshr i64 %c, 8
+  %C = and i64 %sc, 255
+  %sd = lshr i64 %d, 8
+  %D = and i64 %sd, 255
+  %se = lshr i64 %e, 8
+  %E = and i64 %se, 255
+  %sf = lshr i64 %f, 8
+  %F = and i64 %sf, 255
+  %sg = lshr i64 %g, 8
+  %G = and i64 %sg, 255
+  %sh = lshr i64 %h, 8
+  %H = and i64 %sh, 255
+  br label %next
+
+next:
+  %u = add i64 %A, %B
+  %v = add i64 %C, %D
+  %w = add i64 %E, %F
+  %x = add i64 %G, %H
+  %y = add i64 %u, %v
+  %z = add i64 %w, %x
+  %t = add i64 %y, %z
+  ret i64 %t
+}